Premium
Ca 2+ mobilization and capacitative Ca 2+ entry regulate DNA synthesis in cultured chick retinal neuroepithelial cells
Author(s) -
Sugioka Miho,
Zhou WenLiang,
Hofmann HansDieter,
Yamashita Masayuki
Publication year - 1999
Publication title -
international journal of developmental neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.761
H-Index - 88
eISSN - 1873-474X
pISSN - 0736-5748
DOI - 10.1016/s0736-5748(99)00027-1
Subject(s) - neuroepithelial cell , intracellular , retina , biology , dna synthesis , microbiology and biotechnology , retinal , cell culture , embryonic stem cell , biochemistry , in vitro , genetics , neuroscience , gene
Abstract Release of Ca 2+ from intracellular Ca 2+ stores (Ca 2+ mobilization) and capacitative Ca 2+ entry have been shown to be inducible in neuroepithelial cells of the early embryonic chick retina. Both types of Ca 2+ responses decline parallel with retinal progenitor cell proliferation. To investigate their potential role in the regulation of neuroepithelial cell proliferation, we studied the effects of 2,5‐di‐ tert ‐butylhydroquinone (DBHQ), an inhibitor of the Ca 2+ pump of intracellular Ca 2+ stores, and of SK&F 96365, an inhibitor of capacitative Ca 2+ entry, on DNA synthesis in retinal organ cultures from embryonic day 3 (E3) chicks and in dissociated cultures from E7 and E9 chick retinae. We demonstrate that both antagonists inhibit [ 3 H]‐thymidine incorporation in a dose‐dependent manner without affecting cell viability or morphology. The inhibition of [ 3 H]‐thymidine incorporation by SK&F 96365 occurred in the same concentration range (IC 50 : ∼4 μ M) as the blockade of capacitative Ca 2+ entry in the E3 retinal organ culture. At a concentration of 5 μ M SK&F 96365, DNA synthesis was reduced by 71, 40 and 32% in the E3, E7 and E9 cultures, respectively. Application of DBHQ at concentrations which led to depletion of intracellular Ca 2+ stores also inhibited [ 3 H]‐thymidine incorporation with IC 50 values of 20–30 μ M in the different cultures. Our results suggest the involvement of Ca 2+ mobilization and capacitative Ca 2+ entry in the regulation of DNA synthesis in the developing neural retina.